Simple amqp producer script which is tolerant to connection errors

amqp-producer.go

package main

import (
	"encoding/json"
	"flag"
	"fmt"
	linuxproc "github.com/c9s/goprocinfo/linux"
	"github.com/streadway/amqp"
	"log"
	"os"
	"strconv"
	"time"
)

type Configuration struct {
	Hostname  string
	Username  string
	Password  string
	QueueName string
	Vhost     string
}

func ReadConfig(filename string) Configuration {
	file, err := os.Open(filename)
	if err != nil {
		log.Fatal("Can't read config from file:", err)
	}
	defer file.Close()

	decoder := json.NewDecoder(file)
	Config := Configuration{}
	err = decoder.Decode(&Config)
	if err != nil {
		log.Fatal("Can't decode config as JSON:", err)
	}
	return Config
}

func main() {
	c := flag.String("config", "config.json", "Specify the configuration file")
	flag.Parse()

	Config := ReadConfig(*c)
	ConnectionString := fmt.Sprintf(
		"amqp://%s:%s@%s:5672/%s",
		Config.Username,
		Config.Password,
		Config.Hostname,
		Config.Vhost,
	)

	RETRY_SLEEP_DELAY := 1000 * time.Millisecond
	SUCCESS_SLEEP_DELAY := 10000 * time.Millisecond

	for {
		ConnectionHandler, err := amqp.Dial(ConnectionString)
		defer ConnectionHandler.Close()
    if err != nil {
			fmt.Println("Failed to connect to RabbitMQ:", err)
			time.Sleep(RETRY_SLEEP_DELAY)
			continue
		}


		ChannelHandler, err := ConnectionHandler.Channel()
		defer ChannelHandler.Close()
    if err != nil {
			fmt.Println("Failed to open a channel:", err)
			time.Sleep(RETRY_SLEEP_DELAY)
			continue
		}

		QueueHandler, err := ChannelHandler.QueueDeclare(
			Config.QueueName, // name
			false,            // durable
			false,            // delete when unused
			false,            // exclusive
			false,            // no-wait
			nil,              // arguments
		)
		if err != nil {
			fmt.Println("Failed to declare a queue:", err)
			time.Sleep(RETRY_SLEEP_DELAY)
			continue
		}

		stat, err := linuxproc.ReadStat("/proc/stat")
		if err != nil {
			log.Fatal("stat read fail")  // The only way to stop running
		}
		proc_num_str := strconv.FormatUint(stat.Processes, 10)

		err = ChannelHandler.Publish(
			"",                // exchange
			QueueHandler.Name, // routing key
			false,             // mandatory
			false,             // immediate
			amqp.Publishing{
				ContentType: "text/plain",
				Body:        []byte(proc_num_str)})

		if err != nil {
			fmt.Println("Failed to publish a message:", err)
			time.Sleep(RETRY_SLEEP_DELAY)
			continue
		}

		fmt.Println("Sent process count:", proc_num_str)
		time.Sleep(SUCCESS_SLEEP_DELAY)
	}
}